git.sesse.net Git - vlc/blob - modules/codec/subtitles/subsdec.c

   1 /*****************************************************************************
   2  * subsdec.c : text subtitles decoder
   3  *****************************************************************************
   4  * Copyright (C) 2000-2006 the VideoLAN team
   5  * $Id$
   6  *
   7  * Authors: Gildas Bazin <gbazin@videolan.org>
   8  *          Samuel Hocevar <sam@zoy.org>
   9  *          Derk-Jan Hartman <hartman at videolan dot org>
  10  *          Bernie Purcell <bitmap@videolan.org>
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation; either version 2 of the License, or
  15  * (at your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU General Public License
  23  * along with this program; if not, write to the Free Software
  24  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  25  *****************************************************************************/
  26
  27 /*****************************************************************************
  28  * Preamble
  29  *****************************************************************************/
  30
  31 #include "subsdec.h"
  32
  33 /*****************************************************************************
  34  * Local prototypes
  35  *****************************************************************************/
  36 static int  OpenDecoder   ( vlc_object_t * );
  37 static void CloseDecoder  ( vlc_object_t * );
  38
  39 static subpicture_t   *DecodeBlock   ( decoder_t *, block_t ** );
  40 static subpicture_t   *ParseText     ( decoder_t *, block_t * );
  41 static char           *StripTags      ( char * );
  42 static char           *CreateHtmlSubtitle ( char * );
  43
  44
  45 /*****************************************************************************
  46  * Module descriptor.
  47  *****************************************************************************/
  48 static const char *ppsz_encodings[] = { DEFAULT_NAME, "ASCII", "UTF-8", "",
  49     "ISO-8859-1", "CP1252", "MacRoman", "MacIceland","ISO-8859-15", "",
  50     "ISO-8859-2", "CP1250", "MacCentralEurope", "MacCroatian", "MacRomania", "",
  51     "ISO-8859-5", "CP1251", "MacCyrillic", "MacUkraine", "KOI8-R", "KOI8-U", "KOI8-RU", "",
  52     "ISO-8859-6", "CP1256", "MacArabic", "",
  53     "ISO-8859-7", "CP1253", "MacGreek", "",
  54     "ISO-8859-8", "CP1255", "MacHebrew", "",
  55     "ISO-8859-9", "CP1254", "MacTurkish", "",
  56     "ISO-8859-13", "CP1257", "",
  57     "ISO-2022-JP", "ISO-2022-JP-1", "ISO-2022-JP-2", "EUC-JP", "SHIFT_JIS", "",
  58     "ISO-2022-CN", "ISO-2022-CN-EXT", "EUC-CN", "EUC-TW", "BIG5", "BIG5-HKSCS", "",
  59     "ISO-2022-KR", "EUC-KR", "",
  60     "MacThai", "KOI8-T", "",
  61     "ISO-8859-3", "ISO-8859-4", "ISO-8859-10", "ISO-8859-14", "ISO-8859-16", "",
  62     "CP850", "CP862", "CP866", "CP874", "CP932", "CP949", "CP950", "CP1133", "CP1258", "",
  63     "Macintosh", "",
  64     "UTF-7", "UTF-16", "UTF-16BE", "UTF-16LE", "UTF-32", "UTF-32BE", "UTF-32LE",
  65     "C99", "JAVA", "UCS-2", "UCS-2BE", "UCS-2LE", "UCS-4", "UCS-4BE", "UCS-4LE", "",
  66     "HZ", "GBK", "GB18030", "JOHAB", "ARMSCII-8",
  67     "Georgian-Academy", "Georgian-PS", "TIS-620", "MuleLao-1", "VISCII", "TCVN",
  68     "HPROMAN8", "NEXTSTEP" };
  69 /*
  70 SSA supports charset selection.
  71 The following known charsets are used:
  72
  73 0 = Ansi - Western European
  74 1 = default
  75 2 = symbol
  76 3 = invalid
  77 77 = Mac
  78 128 = Japanese (Shift JIS)
  79 129 = Hangul
  80 130 = Johab
  81 134 = GB2312 Simplified Chinese
  82 136 = Big5 Traditional Chinese
  83 161 = Greek
  84 162 = Turkish
  85 163 = Vietnamese
  86 177 = Hebrew
  87 178 = Arabic
  88 186 = Baltic
  89 204 = Russian (Cyrillic)
  90 222 = Thai
  91 238 = Eastern European
  92 254 = PC 437
  93 */
  94
  95 static int  pi_justification[] = { 0, 1, 2 };
  96 static const char *ppsz_justification_text[] = {N_("Center"),N_("Left"),N_("Right")};
  97
  98 #define ENCODING_TEXT N_("Subtitles text encoding")
  99 #define ENCODING_LONGTEXT N_("Set the encoding used in text subtitles")
 100 #define ALIGN_TEXT N_("Subtitles justification")
 101 #define ALIGN_LONGTEXT N_("Set the justification of subtitles")
 102 #define AUTODETECT_UTF8_TEXT N_("UTF-8 subtitles autodetection")
 103 #define AUTODETECT_UTF8_LONGTEXT N_("This enables automatic detection of " \
 104             "UTF-8 encoding within subtitles files.")
 105 #define FORMAT_TEXT N_("Formatted Subtitles")
 106 #define FORMAT_LONGTEXT N_("Some subtitle formats allow for text formatting. " \
 107  "VLC partly implements this, but you can choose to disable all formatting.")
 108
 109
 110 vlc_module_begin();
 111     set_shortname( _("Subtitles"));
 112     set_description( _("Text subtitles decoder") );
 113     set_capability( "decoder", 50 );
 114     set_callbacks( OpenDecoder, CloseDecoder );
 115     set_category( CAT_INPUT );
 116     set_subcategory( SUBCAT_INPUT_SCODEC );
 117
 118     add_integer( "subsdec-align", 0, NULL, ALIGN_TEXT, ALIGN_LONGTEXT,
 119                  VLC_FALSE );
 120         change_integer_list( pi_justification, ppsz_justification_text, 0 );
 121     add_string( "subsdec-encoding", DEFAULT_NAME, NULL,
 122                 ENCODING_TEXT, ENCODING_LONGTEXT, VLC_FALSE );
 123         change_string_list( ppsz_encodings, 0, 0 );
 124     add_bool( "subsdec-autodetect-utf8", VLC_TRUE, NULL,
 125               AUTODETECT_UTF8_TEXT, AUTODETECT_UTF8_LONGTEXT, VLC_FALSE );
 126     add_bool( "subsdec-formatted", VLC_TRUE, NULL, FORMAT_TEXT, FORMAT_LONGTEXT,
 127                  VLC_FALSE );
 128 vlc_module_end();
 129
 130 /*****************************************************************************
 131  * OpenDecoder: probe the decoder and return score
 132  *****************************************************************************
 133  * Tries to launch a decoder and return score so that the interface is able
 134  * to chose.
 135  *****************************************************************************/
 136 static int OpenDecoder( vlc_object_t *p_this )
 137 {
 138     decoder_t     *p_dec = (decoder_t*)p_this;
 139     decoder_sys_t *p_sys;
 140     vlc_value_t    val;
 141
 142     if( p_dec->fmt_in.i_codec != VLC_FOURCC('s','u','b','t') &&
 143         p_dec->fmt_in.i_codec != VLC_FOURCC('s','s','a',' ') )
 144     {
 145         return VLC_EGENERIC;
 146     }
 147
 148     p_dec->pf_decode_sub = DecodeBlock;
 149
 150     /* Allocate the memory needed to store the decoder's structure */
 151     if( ( p_dec->p_sys = p_sys =
 152           (decoder_sys_t *)calloc(1, sizeof(decoder_sys_t)) ) == NULL )
 153     {
 154         msg_Err( p_dec, "out of memory" );
 155         return VLC_ENOMEM;
 156     }
 157
 158     /* init of p_sys */
 159     p_sys->i_align = 0;
 160     p_sys->iconv_handle = (vlc_iconv_t)-1;
 161     p_sys->b_autodetect_utf8 = VLC_FALSE;
 162     p_sys->b_ass = VLC_FALSE;
 163     p_sys->i_original_height = -1;
 164     p_sys->i_original_width = -1;
 165     TAB_INIT( p_sys->i_ssa_styles, p_sys->pp_ssa_styles );
 166     TAB_INIT( p_sys->i_images, p_sys->pp_images );
 167
 168     char *psz_charset = NULL;
 169     /* First try demux-specified encoding */
 170     if( p_dec->fmt_in.subs.psz_encoding && *p_dec->fmt_in.subs.psz_encoding )
 171     {
 172         psz_charset = strdup (p_dec->fmt_in.subs.psz_encoding);
 173         msg_Dbg (p_dec, "trying demuxer-specified character encoding: %s",
 174                  p_dec->fmt_in.subs.psz_encoding ?: "not specified");
 175     }
 176
 177     /* Second, try configured encoding */
 178     if (psz_charset == NULL)
 179     {
 180         psz_charset = var_CreateGetNonEmptyString (p_dec, "subsdec-encoding");
 181         if ((psz_charset != NULL) && !strcasecmp (psz_charset, DEFAULT_NAME))
 182         {
 183             free (psz_charset);
 184             psz_charset = NULL;
 185         }
 186
 187         msg_Dbg (p_dec, "trying configured character encoding: %s",
 188                  psz_charset ?: "not specified");
 189     }
 190
 191     /* Third, try "local" encoding with optional UTF-8 autodetection */
 192     if (psz_charset == NULL)
 193     {
 194         psz_charset = strdup (GetFallbackEncoding ());
 195         msg_Dbg (p_dec, "trying default character encoding: %s",
 196                  psz_charset ?: "not specified");
 197
 198         if (var_CreateGetBool (p_dec, "subsdec-autodetect-utf8"))
 199         {
 200             msg_Dbg (p_dec, "using automatic UTF-8 detection");
 201             p_sys->b_autodetect_utf8 = VLC_TRUE;
 202         }
 203     }
 204
 205     if (psz_charset == NULL)
 206     {
 207         psz_charset = strdup ("UTF-8");
 208         msg_Dbg (p_dec, "trying hard-coded character encoding: %s",
 209                  psz_charset ?: "error");
 210     }
 211
 212     if (psz_charset == NULL)
 213     {
 214         free (p_sys);
 215         return VLC_ENOMEM;
 216     }
 217
 218     if (strcasecmp (psz_charset, "UTF-8") && strcasecmp (psz_charset, "utf8"))
 219     {
 220         p_sys->iconv_handle = vlc_iconv_open ("UTF-8", psz_charset);
 221         if (p_sys->iconv_handle == (vlc_iconv_t)(-1))
 222             msg_Err (p_dec, "cannot convert from %s: %s", psz_charset,
 223                      strerror (errno));
 224     }
 225     free (psz_charset);
 226
 227     var_Create( p_dec, "subsdec-align", VLC_VAR_INTEGER | VLC_VAR_DOINHERIT );
 228     var_Get( p_dec, "subsdec-align", &val );
 229     p_sys->i_align = val.i_int;
 230
 231     if( p_dec->fmt_in.i_codec == VLC_FOURCC('s','s','a',' ') && var_CreateGetBool( p_dec, "subsdec-formatted" ) )
 232     {
 233         if( p_dec->fmt_in.i_extra > 0 )
 234             ParseSSAHeader( p_dec );
 235     }
 236
 237     return VLC_SUCCESS;
 238 }
 239
 240 /****************************************************************************
 241  * DecodeBlock: the whole thing
 242  ****************************************************************************
 243  * This function must be fed with complete subtitles units.
 244  ****************************************************************************/
 245 static subpicture_t *DecodeBlock( decoder_t *p_dec, block_t **pp_block )
 246 {
 247     subpicture_t *p_spu = NULL;
 248
 249     if( !pp_block || *pp_block == NULL ) return NULL;
 250
 251     p_spu = ParseText( p_dec, *pp_block );
 252
 253     block_Release( *pp_block );
 254     *pp_block = NULL;
 255
 256     return p_spu;
 257 }
 258
 259 /*****************************************************************************
 260  * CloseDecoder: clean up the decoder
 261  *****************************************************************************/
 262 static void CloseDecoder( vlc_object_t *p_this )
 263 {
 264     decoder_t *p_dec = (decoder_t *)p_this;
 265     decoder_sys_t *p_sys = p_dec->p_sys;
 266
 267     if( p_sys->iconv_handle != (vlc_iconv_t)-1 )
 268         vlc_iconv_close( p_sys->iconv_handle );
 269
 270     if( p_sys->pp_ssa_styles )
 271     {
 272         int i;
 273         for( i = 0; i < p_sys->i_ssa_styles; i++ )
 274         {
 275             if( !p_sys->pp_ssa_styles[i] )
 276                 continue;
 277
 278             if( p_sys->pp_ssa_styles[i]->psz_stylename )
 279                 free( p_sys->pp_ssa_styles[i]->psz_stylename );
 280             if( p_sys->pp_ssa_styles[i]->font_style.psz_fontname )
 281                 free( p_sys->pp_ssa_styles[i]->font_style.psz_fontname );
 282             if( p_sys->pp_ssa_styles[i] )
 283                 free( p_sys->pp_ssa_styles[i] );
 284         }
 285         TAB_CLEAN( p_sys->i_ssa_styles, p_sys->pp_ssa_styles );
 286     }
 287     if( p_sys->pp_images )
 288     {
 289         int i;
 290         for( i = 0; i < p_sys->i_images; i++ )
 291         {
 292             if( !p_sys->pp_images[i] )
 293                 continue;
 294
 295             if( p_sys->pp_images[i]->p_pic )
 296                 p_sys->pp_images[i]->p_pic->pf_release( p_sys->pp_images[i]->p_pic );
 297             if( p_sys->pp_images[i]->psz_filename )
 298                 free( p_sys->pp_images[i]->psz_filename );
 299
 300             free( p_sys->pp_images[i] );
 301         }
 302         TAB_CLEAN( p_sys->i_images, p_sys->pp_images );
 303     }
 304
 305     free( p_sys );
 306 }
 307
 308 /*****************************************************************************
 309  * ParseText: parse an text subtitle packet and send it to the video output
 310  *****************************************************************************/
 311 static subpicture_t *ParseText( decoder_t *p_dec, block_t *p_block )
 312 {
 313     decoder_sys_t *p_sys = p_dec->p_sys;
 314     subpicture_t *p_spu = NULL;
 315     char *psz_subtitle = NULL;
 316     video_format_t fmt;
 317
 318     /* We cannot display a subpicture with no date */
 319     if( p_block->i_pts == 0 )
 320     {
 321         msg_Warn( p_dec, "subtitle without a date" );
 322         return NULL;
 323     }
 324
 325     /* Check validity of packet data */
 326     /* An "empty" line containing only \0 can be used to force
 327        and ephemer picture from the screen */
 328     if( p_block->i_buffer < 1 )
 329     {
 330         msg_Warn( p_dec, "no subtitle data" );
 331         return NULL;
 332     }
 333
 334     /* Should be resiliant against bad subtitles */
 335     psz_subtitle = strndup( (const char *)p_block->p_buffer,
 336                             p_block->i_buffer );
 337     if( psz_subtitle == NULL )
 338         return NULL;
 339
 340     if( p_sys->iconv_handle == (vlc_iconv_t)-1 )
 341     {
 342         if (EnsureUTF8( psz_subtitle ) == NULL)
 343         {
 344             msg_Err( p_dec, _("failed to convert subtitle encoding.\n"
 345                      "Try manually setting a character-encoding "
 346                      "before you open the file.") );
 347         }
 348     }
 349     else
 350     {
 351
 352         if( p_sys->b_autodetect_utf8 )
 353         {
 354             if( IsUTF8( psz_subtitle ) == NULL )
 355             {
 356                 msg_Dbg( p_dec, "invalid UTF-8 sequence: "
 357                          "disabling UTF-8 subtitles autodetection" );
 358                 p_sys->b_autodetect_utf8 = VLC_FALSE;
 359             }
 360         }
 361
 362         if( !p_sys->b_autodetect_utf8 )
 363         {
 364             size_t inbytes_left = strlen( psz_subtitle );
 365             size_t outbytes_left = 6 * inbytes_left;
 366             char *psz_new_subtitle = malloc( outbytes_left + 1 );
 367             char *psz_convert_buffer_out = psz_new_subtitle;
 368             const char *psz_convert_buffer_in = psz_subtitle;
 369
 370             size_t ret = vlc_iconv( p_sys->iconv_handle,
 371                                     &psz_convert_buffer_in, &inbytes_left,
 372                                     &psz_convert_buffer_out, &outbytes_left );
 373
 374             *psz_convert_buffer_out++ = '\0';
 375             free( psz_subtitle );
 376
 377             if( ( ret == (size_t)(-1) ) || inbytes_left )
 378             {
 379                 free( psz_new_subtitle );
 380                 msg_Err( p_dec, _("failed to convert subtitle encoding.\n"
 381                         "Try manually setting a character-encoding "
 382                                 "before you open the file.") );
 383                 return NULL;
 384             }
 385
 386             psz_subtitle = realloc( psz_new_subtitle,
 387                                     psz_convert_buffer_out - psz_new_subtitle );
 388         }
 389     }
 390
 391     /* Create the subpicture unit */
 392     p_spu = p_dec->pf_spu_buffer_new( p_dec );
 393     if( !p_spu )
 394     {
 395         msg_Warn( p_dec, "can't get spu buffer" );
 396         if( psz_subtitle ) free( psz_subtitle );
 397         return NULL;
 398     }
 399
 400     p_spu->b_pausable = VLC_TRUE;
 401
 402     /* Create a new subpicture region */
 403     memset( &fmt, 0, sizeof(video_format_t) );
 404     fmt.i_chroma = VLC_FOURCC('T','E','X','T');
 405     fmt.i_aspect = 0;
 406     fmt.i_width = fmt.i_height = 0;
 407     fmt.i_x_offset = fmt.i_y_offset = 0;
 408     p_spu->p_region = p_spu->pf_create_region( VLC_OBJECT(p_dec), &fmt );
 409     if( !p_spu->p_region )
 410     {
 411         msg_Err( p_dec, "cannot allocate SPU region" );
 412         if( psz_subtitle ) free( psz_subtitle );
 413         p_dec->pf_spu_buffer_del( p_dec, p_spu );
 414         return NULL;
 415     }
 416
 417     /* Decode and format the subpicture unit */
 418     if( p_dec->fmt_in.i_codec != VLC_FOURCC('s','s','a',' ') )
 419     {
 420         /* Normal text subs, easy markup */
 421         p_spu->p_region->i_align = SUBPICTURE_ALIGN_BOTTOM | p_sys->i_align;
 422         p_spu->i_x = p_sys->i_align ? 20 : 0;
 423         p_spu->i_y = 10;
 424
 425         /* Remove formatting from string */
 426
 427         p_spu->p_region->psz_text = StripTags( psz_subtitle );
 428         if( var_CreateGetBool( p_dec, "subsdec-formatted" ) )
 429         {
 430             p_spu->p_region->psz_html = CreateHtmlSubtitle( psz_subtitle );
 431         }
 432
 433         p_spu->i_start = p_block->i_pts;
 434         p_spu->i_stop = p_block->i_pts + p_block->i_length;
 435         p_spu->b_ephemer = (p_block->i_length == 0);
 436         p_spu->b_absolute = VLC_FALSE;
 437     }
 438     else
 439     {
 440         /* Decode SSA/USF strings */
 441         if( p_dec->fmt_in.i_codec == VLC_FOURCC('s','s','a',' ') )
 442             ParseSSAString( p_dec, psz_subtitle, p_spu );
 443
 444         p_spu->i_start = p_block->i_pts;
 445         p_spu->i_stop = p_block->i_pts + p_block->i_length;
 446         p_spu->b_ephemer = (p_block->i_length == 0);
 447         p_spu->b_absolute = VLC_FALSE;
 448         p_spu->i_original_picture_width = p_sys->i_original_width;
 449         p_spu->i_original_picture_height = p_sys->i_original_height;
 450     }
 451     if( psz_subtitle ) free( psz_subtitle );
 452
 453     return p_spu;
 454 }
 455
 456 char* GotoNextLine( char *psz_text )
 457 {
 458     char *p_newline = psz_text;
 459
 460     while( p_newline[0] != '\0' )
 461     {
 462         if( p_newline[0] == '\n' || p_newline[0] == '\r' )
 463         {
 464             p_newline++;
 465             while( p_newline[0] == '\n' || p_newline[0] == '\r' )
 466                 p_newline++;
 467             break;
 468         }
 469         else p_newline++;
 470     }
 471     return p_newline;
 472 }
 473
 474 /* Function now handles tags which has attribute values, and tries
 475  * to deal with &' commands too. It no longer modifies the string
 476  * in place, so that the original text can be reused
 477  */
 478 static char *StripTags( char *psz_subtitle )
 479 {
 480     char *psz_text_start;
 481     char *psz_text;
 482
 483     psz_text = psz_text_start = malloc( strlen( psz_subtitle ) + 1 );
 484     if( !psz_text_start )
 485         return NULL;
 486
 487     while( *psz_subtitle )
 488     {
 489         if( *psz_subtitle == '<' )
 490         {
 491             if( strncasecmp( psz_subtitle, "<br/>", 5 ) == 0 )
 492                 *psz_text++ = '\n';
 493
 494             psz_subtitle += strcspn( psz_subtitle, ">" );
 495         }
 496         else if( *psz_subtitle == '&' )
 497         {
 498             if( !strncasecmp( psz_subtitle, "&lt;", 4 ))
 499             {
 500                 *psz_text++ = '<';
 501                 psz_subtitle += strcspn( psz_subtitle, ";" );
 502             }
 503             else if( !strncasecmp( psz_subtitle, "&gt;", 4 ))
 504             {
 505                 *psz_text++ = '>';
 506                 psz_subtitle += strcspn( psz_subtitle, ";" );
 507             }
 508             else if( !strncasecmp( psz_subtitle, "&amp;", 5 ))
 509             {
 510                 *psz_text++ = '&';
 511                 psz_subtitle += strcspn( psz_subtitle, ";" );
 512             }
 513             else if( !strncasecmp( psz_subtitle, "&quot;", 6 ))
 514             {
 515                 *psz_text++ = '\"';
 516                 psz_subtitle += strcspn( psz_subtitle, ";" );
 517             }
 518             else
 519             {
 520                 /* Assume it is just a normal ampersand */
 521                 *psz_text++ = '&';
 522             }
 523         }
 524         else
 525         {
 526             *psz_text++ = *psz_subtitle;
 527         }
 528
 529         psz_subtitle++;
 530     }
 531     *psz_text = '\0';
 532     psz_text_start = realloc( psz_text_start, strlen( psz_text_start ) + 1 );
 533
 534     return psz_text_start;
 535 }
 536
 537 /* Try to respect any style tags present in the subtitle string. The main
 538  * problem here is a lack of adequate specs for the subtitle formats.
 539  * SSA/ASS and USF are both detail spec'ed -- but they are handled elsewhere.
 540  * SAMI has a detailed spec, but extensive rework is needed in the demux
 541  * code to prevent all this style information being excised, as it presently
 542  * does.
 543  * That leaves the others - none of which were (I guess) originally intended
 544  * to be carrying style information. Over time people have used them that way.
 545  * In the absence of specifications from which to work, the tags supported
 546  * have been restricted to the simple set permitted by the USF DTD, ie. :
 547  *  Basic: <br>, <i>, <b>, <u>
 548  *  Extended: <font>
 549  *    Attributes: face
 550  *                family
 551  *                size
 552  *                color
 553  *                outline-color
 554  *                shadow-color
 555  *                outline-level
 556  *                shadow-level
 557  *                back-color
 558  *                alpha
 559  * There is also the further restriction that the subtitle be well-formed
 560  * as an XML entity, ie. the HTML sentence:
 561  *        <b><i>Bold and Italics</b></i>
 562  * doesn't qualify because the tags aren't nested one inside the other.
 563  * <text> tags are automatically added to the output to ensure
 564  * well-formedness.
 565  * If the text doesn't qualify for any reason, a NULL string is
 566  * returned, and the rendering engine will fall back to the
 567  * plain text version of the subtitle.
 568  */
 569 static char *CreateHtmlSubtitle( char *psz_subtitle )
 570 {
 571     char    psz_tagStack[ 100 ];
 572     size_t  i_buf_size     = strlen( psz_subtitle ) + 100;
 573     char   *psz_html_start = malloc( i_buf_size );
 574
 575     psz_tagStack[ 0 ] = '\0';
 576
 577     if( psz_html_start != NULL )
 578     {
 579         char *psz_html = psz_html_start;
 580
 581         strcpy( psz_html, "<text>" );
 582         psz_html += 6;
 583
 584         while( *psz_subtitle )
 585         {
 586             if( *psz_subtitle == '\n' )
 587             {
 588                 strcpy( psz_html, "<br/>" );
 589                 psz_html += 5;
 590                 psz_subtitle++;
 591             }
 592             else if( *psz_subtitle == '<' )
 593             {
 594                 if( !strncasecmp( psz_subtitle, "<br/>", 5 ))
 595                 {
 596                     strcpy( psz_html, "<br/>" );
 597                     psz_html += 5;
 598                     psz_subtitle += 5;
 599                 }
 600                 else if( !strncasecmp( psz_subtitle, "<b>", 3 ) )
 601                 {
 602                     strcpy( psz_html, "<b>" );
 603                     strcat( psz_tagStack, "b" );
 604                     psz_html += 3;
 605                     psz_subtitle += 3;
 606                 }
 607                 else if( !strncasecmp( psz_subtitle, "<i>", 3 ) )
 608                 {
 609                     strcpy( psz_html, "<i>" );
 610                     strcat( psz_tagStack, "i" );
 611                     psz_html += 3;
 612                     psz_subtitle += 3;
 613                 }
 614                 else if( !strncasecmp( psz_subtitle, "<u>", 3 ) )
 615                 {
 616                     strcpy( psz_html, "<u>" );
 617                     strcat( psz_tagStack, "u" );
 618                     psz_html += 3;
 619                     psz_subtitle += 3;
 620                 }
 621                 else if( !strncasecmp( psz_subtitle, "<font ", 6 ))
 622                 {
 623                     const char *psz_attribs[] = { "face=\"", "family=\"", "size=\"",
 624                             "color=\"", "outline-color=\"", "shadow-color=\"",
 625                             "outline-level=\"", "shadow-level=\"", "back-color=\"",
 626                             "alpha=\"", NULL };
 627
 628                     strcpy( psz_html, "<font " );
 629                     strcat( psz_tagStack, "f" );
 630                     psz_html += 6;
 631                     psz_subtitle += 6;
 632
 633                     while( *psz_subtitle != '>' )
 634                     {
 635                         int  k;
 636
 637                         for( k=0; psz_attribs[ k ]; k++ )
 638                         {
 639                             int i_len = strlen( psz_attribs[ k ] );
 640
 641                             if( !strncasecmp( psz_subtitle, psz_attribs[ k ], i_len ))
 642                             {
 643                                 i_len += strcspn( psz_subtitle + i_len, "\"" ) + 1;
 644
 645                                 strncpy( psz_html, psz_subtitle, i_len );
 646                                 psz_html += i_len;
 647                                 psz_subtitle += i_len;
 648                                 break;
 649                             }
 650                         }
 651                         if( psz_attribs[ k ] == NULL )
 652                         {
 653                             /* Jump over unrecognised tag */
 654                             int i_len = strcspn( psz_subtitle, "\"" ) + 1;
 655
 656                             i_len += strcspn( psz_subtitle + i_len, "\"" ) + 1;
 657                             psz_subtitle += i_len;
 658                         }
 659                         while (*psz_subtitle == ' ')
 660                             *psz_html++ = *psz_subtitle++;
 661                     }
 662                     *psz_html++ = *psz_subtitle++;
 663                 }
 664                 else if( !strncmp( psz_subtitle, "</", 2 ))
 665                 {
 666                     vlc_bool_t  b_match     = VLC_FALSE;
 667                     int         i_len       = strlen( psz_tagStack ) - 1;
 668                     char       *psz_lastTag = NULL;
 669
 670                     if( i_len >= 0 )
 671                     {
 672                         psz_lastTag = psz_tagStack + i_len;
 673                         i_len = 0;
 674
 675                         switch( *psz_lastTag )
 676                         {
 677                             case 'b':
 678                                 b_match = !strncasecmp( psz_subtitle, "</b>", 4 );
 679                                 i_len   = 4;
 680                                 break;
 681                             case 'i':
 682                                 b_match = !strncasecmp( psz_subtitle, "</i>", 4 );
 683                                 i_len   = 4;
 684                                 break;
 685                             case 'u':
 686                                 b_match = !strncasecmp( psz_subtitle, "</u>", 4 );
 687                                 i_len   = 4;
 688                                 break;
 689                             case 'f':
 690                                 b_match = !strncasecmp( psz_subtitle, "</font>", 7 );
 691                                 i_len   = 7;
 692                                 break;
 693                         }
 694                     }
 695                     if( ! b_match )
 696                     {
 697                         /* Not well formed -- kill everything */
 698                         free( psz_html_start );
 699                         psz_html_start = NULL;
 700                         break;
 701                     }
 702                     *psz_lastTag = '\0';
 703                     strncpy( psz_html, psz_subtitle, i_len );
 704                     psz_html += i_len;
 705                     psz_subtitle += i_len;
 706                 }
 707                 else
 708                 {
 709                     psz_subtitle += strcspn( psz_subtitle, ">" );
 710                 }
 711             }
 712             else if( *psz_subtitle == '&' )
 713             {
 714                 if( !strncasecmp( psz_subtitle, "&lt;", 4 ))
 715                 {
 716                     strcpy( psz_html, "&lt;" );
 717                     psz_html += 4;
 718                     psz_subtitle += 4;
 719                 }
 720                 else if( !strncasecmp( psz_subtitle, "&gt;", 4 ))
 721                 {
 722                     strcpy( psz_html, "&gt;" );
 723                     psz_html += 4;
 724                     psz_subtitle += 4;
 725                 }
 726                 else if( !strncasecmp( psz_subtitle, "&amp;", 5 ))
 727                 {
 728                     strcpy( psz_html, "&amp;" );
 729                     psz_html += 5;
 730                     psz_subtitle += 5;
 731                 }
 732                 else
 733                 {
 734                     strcpy( psz_html, "&amp;" );
 735                     psz_html += 5;
 736                     psz_subtitle++;
 737                 }
 738             }
 739             else
 740             {
 741                 *psz_html = *psz_subtitle;
 742                 if( psz_html > psz_html_start )
 743                 {
 744                     /* Check for double whitespace */
 745                     if((( *psz_html == ' ' ) ||
 746                         ( *psz_html == '\t' )) &&
 747                        (( *(psz_html-1) == ' ' ) ||
 748                         ( *(psz_html-1) == '\t' )))
 749                     {
 750                         strcpy( psz_html, NO_BREAKING_SPACE );
 751                         psz_html += strlen( NO_BREAKING_SPACE ) - 1;
 752                     }
 753                 }
 754                 psz_html++;
 755                 psz_subtitle++;
 756             }
 757
 758             if( ( size_t )( psz_html - psz_html_start ) > i_buf_size - 10 )
 759             {
 760                 int i_len = psz_html - psz_html_start;
 761
 762                 i_buf_size += 100;
 763                 psz_html_start = realloc( psz_html_start, i_buf_size );
 764                 psz_html = psz_html_start + i_len;
 765                 *psz_html = '\0';
 766             }
 767         }
 768         strcpy( psz_html, "</text>" );
 769         psz_html += 7;
 770
 771         if( psz_tagStack[ 0 ] != '\0' )
 772         {
 773             /* Not well formed -- kill everything */
 774             free( psz_html_start );
 775             psz_html_start = NULL;
 776         }
 777         else if( psz_html_start )
 778         {
 779             /* Shrink the memory requirements */
 780             psz_html_start = realloc( psz_html_start,  psz_html - psz_html_start + 1 );
 781         }
 782     }
 783     return psz_html_start;
 784 }